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Name: Glenn M.
Status: educator
Age: 30s
Location: N/A
Country: N/A
Date: 1999-2001 


Question:
I understand why the leaves change color. If chlorophyll is the same then why does not grass or conifers change color in the autumn.


Replies:
Deciduous plants lose their leaves by winter; evergreen plants retain their leaves much longer, but they too, eventually lose their leaves or needles. There are conifers that do change color early in autumn and lose their needles by winter.

http://www.growinglifestyle.com/article/s0/a65614.html

http://www.bcforestryinfo.com/forestry/trees/tamarack.htm

http://www.arborquest.com/SPdetail.cfm?sp=LALAAA

Sincerely,

Anthony R. Brach


Certain trees, for example red maples, have colored substances in the leaves in addition to chlorophyll. During the spring and summer the color of these other substances are overwhelmed by the intense green color of chlorophyll. In the autumn when the chlorophyll is no longer present, these underlying substances show off their color. Other plants, e.g. most grasses I can think of, do not have any of these colored substances, so in the autumn they just turn brown.

Vince Calder


It is simply a matter of different adaptations to seasonal changes. Most conifers have leaves with small surface area and waxy coating to reduce water loss in winter, which is more of a problem to many plants than temperature. Lawn grasses and many other plants have natural "antifreeze" like components in their leaves that keep tissues from being destroyed by freezing. Interestingly many of our native prairie grasses do turn subtle but very lovely colors in fall as they enter winter dormancy.

J. Elliott



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